A new study suggests that the best answer might be the last one. According to a research team led by Ondrej Mottl and Suzette G.A. Flantua of the University of Bergen in Norway, the vegetation of the planet began changing dramatically between 4.6 and 2.9 thousand years ago, and it’s likely that the primary cause was human activity—agriculture, deforestation, and the use of fire to clear landscapes.
Scientists - Something Fox News discounts as something that does not exist - Except of course to produce Virus protection and Moon and Mars landers etc etc
(Edited 1 minute later.)
@previous (Syntax)(Edited 34 seconds later.)